Kojima literally said right before he showed this, that this is a sneak peak as he's going to do a real gameplay demonstration at TGS and you guys like Resetera go and forget that the release date trailer has already shown that there's bike riding, melee combat, shooting and boss like encounters in the game.

You're getting trolled by a trailer that starts with pissing out a mushroom and ends with walking straight down a cliff, I mean have you forgotten the cardboard boxes and the chicken hat from his last game? Dude just has a weird sense of humor.